Barrel lock for automatic firearms



Oct. 10, G.'WEBB 25,360,293-

BARREL LOOK FOR AUTOMATIC FIREARMS Original Filed Jan. 1'7, 1940 2 Sheets-Sheet 1 Webb 2 Sheet-Sheet 2 Ji l/522202" A 550 I G WEBB BARREL LOOK FOR AUTOMATIC FIREARMS Original Filed Jan. 17, 1940 Patented Oct. 10, 1944 UNETE BARREL LOOK FOR AUTOMATIC FIREARMS George Webb, Hartford, Conn., assignor to Colts Patent Fire Arms Manufacturing Company, Hartford, Conn., a corporation of Connecticut 5 Claims.

The present invention relates to a barrel lock for an automatic firearm of the type shown in its entirety in Browning Patent 1,525,065 and in copending application, Serial No. 325,405 filed March 2.2, 1940. This application is a division of copending application Serial No. 314,271, filed J anuary 17, 1940, now Patent No. 2,297,640, which relates to breech mechanism for automatic firearms.

It is an object of the present invention to provide a simple and readily releasable lock for preventing rotatable movement of the firearm barrel or tube with respect to the breech casing and more particularly with respect to the barrel extension of the firearm. The barrel and barrel extension reciprocate as a unit during operation of the gun and the barrel is disconnectible from the barrel extension upon rotation, but rotation of the barrel is normally prevented by a detent which moves bodily with the said barrel and barrel extension. In accordance with the invention, this detent can be released to permit rotation of the barrel, such release being effected by means of a manually operable device which is A,

exteriorly accessible and which does not partake of the reciprocated movement referred to. Also in accordance with the invention, the detent for holding the barrel is so mounted and controlled and is also of such proportions that th barrel can be screwed into its fully connected position without manual withdrawal or other manual manipulation of the detent and, following the initial manual withdrawal of the detent, the barrel can be freely unscrewed from the barrel extension without further manual manipulation of the detent.

In the accompanying drawings I have shown the embodiment of the invention which I now deem preferable but it will be understood that the drawings are intended for illustrative purposes only and are not to be construed as defining or limit-v ing the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

In the drawings:

Fig, 1 is a fragmentary side view of a gun embodying the invention, a certain portion being broken away to show interior parts.

Fig. 2 is an enlarged fragmentary vertical sectional view taken along the line 22 of Fig. 1.

Fig. 3 is an enlarged fragmentary plan view showing the device for moving the barrel locking detent.

Fig. 4 is a fragmentary sectional view taken along the line 4-4 of Fig. 2.

Fig. 5 is a fragmentary horizontal sectional.

View taken generally along the line 55 of Fig. 2 and showing the barrel in its locked position.

Fig. 6 is a View similar to Fig. 5 but showing the barrel in the position which it occupies just before engagement with the barrel locking detent.

Referring to the drawings, I represents the main casing which comprises spaced side plates I and I connected near their front ends with a trunnion block 2. At the top of the casing is a feed box 3 and at the rear of the feed .box is a trigger 4. These parts need not be described in detail as the invention does not relate to the details of the feed mechanism or of the firing mechanism. At the front and rear of the feed box are cover plates 5 and 6 which connect the side plates I and l The barrel I is longitudinally movable in an opening in the trunnion block and it is detachably connected with a barrel extension 8 which is longitudinally movable in the casing, being guided at the top and at the bottom by inward pro jecting flanges on the side plates I and I The barrel extension comprises two spaced legs 8 The barrel and barrel extension move rearward upon recoil and are returned in the forward direction by the recuperator spring 9. This spring acts through the recuperator rod 'Iil which is connected at its rear end with a depending lug 8 on the barrel extension 8, thisconnection being b means of a nut Ill as shown clearly in Fig. 1.

Also longitudinally movable within the casing is a lock frame I I, this frame being shown in Fig. 1 in the rearward position, which it occupies at least momentarily after the firing of each shot. Depending from the lock frame II is a yoke I2 to which are connected two transversely spaced tension rods I 3, I3. The depending lug 8 of the barrel extension 8 carries a yoke I4 having laterally projecting arms I l I 4 shown in Fig. 1.

Supported in part on the arms M I i are tubes I5, I5 which receive the tension rods I3, I3 and which also receive reaction springs I5, I 6 surrounding the tension rods. These springs abut at their rear ends against plugs I5 in the rear ends of the tubes, and abut at their forward ends against projections (not shown) on the rods I3 near the forward ends thereof.

Upon recoil, the barrel, barrel extension and lock frame move rearward simultaneously, and the lock frame is at least momentarily held in its rearward position as shown in Fig. l. The barrel and barrel extension immediately move forward under the influence of the recuperator springs It, IS in cooperation with the rods 13, [3, move the lock frame forward, this. frame with its associated parts serving to push a cartridge into the chamber of the barrel as explained in detail in the aforesaid patents.

A breech block I! is provided which moves bodily with the barrel extension 8 and said breech block is also movable vertically with respect to the barrel extension. The breech block is positioned between legs 6 and 8 on the barrel extension and is guided by ribs 8 and 8 formed respectively thereon. The vertical movement of the breech block I! is effected by an actuating lever 18 which has means to engage a slot I1 in the breech block. The actuating lever is carried by a pivotal connection l8 'on the lock frame II and said actuating lever is moved about its pivotal connection by various cams which are described and illustrated in detail in said copending application, Serial No. 314,271. In Fig. 1, the operating lever 18 is shown in full lines in its retracted position. Fig. 1 also shows the operating lever I 8 illustrated in dot-and-dash lines in a position where the operating lever: is just engaging the breech block, which engagement takes place at the beginning of the operation for moving the breech block to elevated or fully breeched position. Inasmuch as a. complete understanding of the operation of actuating lever I8 is not essential to a comprehension of the instant invention, further description of the operating mechanism for the actuating lever is not believed necessary. For further description of the details and functions of said operating mechanism, attention is directed to said co-pending application, Serial No. 314,271.

As already stated, the barrel 1 is detachably connected with the barrel extensionB. The connection between the barrel and the barrel extension is of such character that these parts can be detached by rotary movement of the barrel and Ill have shown for this purpose a simple threaded connection at 21. In order to prevent unintended rotative movement of the barrel 1, a detent 28 is movably mounted in a longitudinal hole in the barrel extension, as shown in Figs. 5 and 6, this detent being pressed in the forward direction by means of a spring 29. A pin 30 is carried by the detent 28, this pin projecting through a slot 3! in the side of the barrel extension. The pin 30 serves to limit longitudinal movement of the detent 28 and also has another function as will presently appear.

The barrel 1 has a notch 32 for receiving the detent 28 and when the detent is entered in the notch, as shownrin Fig. 5, rotation of the barrel is effectively prevented. Preferably, the forward movement of the detent 28 is so limited that its maximum projection forward from the front face of the barrel extension is slightly less than the the notch 32 in register with the detent 28, the

detent does notproject far enough to enter the notch and therefore does not interfere with continued rotation of the barrel in the engaging a member.

direction. Only when the barrel reaches its fully engaged position, as shown in Fig. 5, does the detent enter the notch and prevent rotation of the barrel.

It will be understood from the prior description that the barrel and barrel extension move rearward from the position shown in Fig. 5 during each functioning of the gun. Inasmuch as the barrel and barrel extension normally move as a unit or assembly during the firing of the'gun, the assembled barrel and barrel extension may be termed a barrel assembly for purposes of convenience. In accordance with the invention, I provide a manually operable means for releasing thefdetent '28, this means being so constructed thatitdoes not partake of the bodily movement of the'barrel and barrel extension butnevertheless serves to relatively move the detent 28 when the barrel and barrel extension are in forward position. ,As shown, particularly in Figs. 2, 3 and 4, a slide 33is provided on the top flange of the left side plate l this slidebeing enclosed in and guided by a housing 34 secured to the said top flange. The'slide 33carries 2. depending lug 33" which projects through a slot in the top flange and is positioned at the front of the beforementioned pin 30. A spring 35 serves to bias the slide 33 in the forward'direction and movement of the slide is limited by a pin 36 which projects through a slot in the top wall of the housing 34. A fingerpiece 31 projects laterally from the slide through a slot in the side of the housing 34.

As readily seen from Figs. 2, 4, Sand 6, the

corners of the forward end of the barrel extension 8 are removed to provide cavities or spaces 38. With the forward corners removed, the forward end of the barrel extension is substantially of an octagonalshapeas may be seen from Fig. 2. One of the upper cavities 38 accommodates the depending lug 33 which is carried by the slide 33. The barrel and barrel extension are in their forwardmost position in Fig. 5. When the barrel and barrel extension move in recoil direction upon the firing of a cartridge, the said cavity 38 which accommodates lug 33 affords clearance whereby the barrel and barrel extension may move in recoil direction without engaging said lug. This clearance is evident from Fig. 2. However, when the barrel and barrel extension are in their forward position shown in'Fig. 5, the lug33 is in proper position whereby, upon being moved rearward by the finger piece 31, the lug will engage the pin 30. which is fixed to the detent and move the detent from the notch 32in the barrel, following which the barrel may be rotated in disengaging direction, a

It will be observed that it is not necessary to hold the finger piece retracted after the barrel has started to turn. For the reasons already explained, the detent 28 will not enter the notch 32 when the parts come in register at the end of the first turn.

It will thus be seen that the present invention provides a barrel locking means which is operable by an exteriorly accessible finger'engaging The lockingmeahs proper serves to prevent relative rotatable movement between the barrel and barrel extension and moves therewith during the'functioning of the'gunwhile firing. The construction provides clearance for the operating means of the locking detent whereby when the barrel and barrel extension are ina prede termined position, the operating means' is in position to engage the detent to free the barrel and permit the turning thereof in disengaging direction.

While the invention has been illustrated and described in its preferred embodiment and has included certain details, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other Ways,

falling within the scope of the invention as claimed,

What I claim is:

1. In an automatic firearm, the combination of a casing, a longitudinally reciprocable barrel extension within the casing, a barrel at the forward end of the casing having its breech end connected with the barrel extension I and disconnectible therefrom by rotative movement, a detent bodily movable with the barrel extension and barrel and also relatively thereto, the said detent normally serving to prevent relative rotation of the barrel, and a manually movable exteriorly accessible device mounted on the casing independently of the barrel extension and barrel and so positioned as to be engageable with the detent when the barrel extension and barrel are in a predetermined position, the said device upon being manually moved serving to move the detent relatively to the barrel extension and barrel so as to release the barrel and permit rotation and disconnection thereof.

2. In an automatic firearm, the combination of a casing, a longitudinally reciprocable barrel extension within the casing, a barrel at the forward end of the casing having its breech end connected with the barrel extension and disconnectible therefrom by rotative movement, the said barrel having a detent receiving notch at its breech end, a detent bodily movable with the barrel extension and also longitudinally movable relatively thereto, the said detent being normally entered in the said barrel notch and serving to prevent relative rotation of the barrel, and a longitudinally movable exteriorly accessible device mounted on the casing independently of the barrel extension and barrel and so positioned as to be engageable with the detent when the barrel extension and barrel are in their forward positions, the said device upon being manually moved rearward serving to move the detent rearward so as to Withdraw it from the barrel notch and permit rotation and disconnection of the barrel.

3. In an automatic firearm, the combination of a casing, a longitudinally reciprocable barrel assembly comprising a barrel extension within the casing and a barrel at the forward end of the casing and the barrel having its breech end connected with the barrel extension and disconnectible therefrom by rotative movement, said barrel assembly having a cavity opening outward into the interior of the casing and said barrel assembly also having a detent bodily movable relatively thereto and normally serving to prevent rotation of the barrel relative to the barrel extension,

and a manually movable exteriorly accessible device mounted on the casing independently of the barrel assembly and having a portion projecting into said cavity to permit movement of the barrel assembly independently of said device and said portion being so positioned as to be engageable with the detent when the barrel assembly is in a predetermined position, the said device upon being moved manually serving to move the detent relatively to the barrel assembly to release the barrel for rotation and disconnection from the barrel extension.

4. In an automatic firearm, the combination of a casing, a longitudinally reciprocable barrel extension Within the casing and provided with a cavity opening outward into the interior of the casing, a barrel at the forward end of the casing having its breech end connected with the barrel extension and disconnectible therefrom by rotative movement, a detent mounted in the barrel extension and relatively movable thereto, the said detent being engageable with the barrel to prevent relative rotation of the barrel, and a manually movable exteriorly accessible device mounted on the casing independently of the barrel extension and having a portion projecting into said cavity to permit movement of the barrel extension independently of said device and portion and said portion being so positioned as to be engageable with the detent when the barrel extension and barrel are in a predetermined position, the said device upon being moved manually serving to move the detent relatively to the barrel extension to release the barrel for rotation and disconnection from the barrel extension.

5. In an automatic firearm, the combination of a casing, a longitudinally reciprocable barrel extension within the casing, a barrel at the forward end "of the casing having at its breech end a threaded connection with the barrel extension and also having a detent receiving notch, a spring-pressed detent carried by the barrel extension and adapted to enter the said barrel notch to normally prevent relative rotation of the barrel, the said detent being longitudinally movable relatively to the barrel extension through a distance less than the lead of the thread of the threaded connection and the said detent by reason of its said limited range of movement permitting the barrel to be screwed into fully connected position without withdrawal of the detent, and a longitudinally movable exteriorly accessible device mounted on the casing independently of the barrel extension and barrel and so positioned as to be engageable with the detent when the barrel extension and barrel are in their forward positions, the said device upon 

